1. Field of the Invention
The embodiment discussed herein relates to a radar device.
2. Description of the Related Art
Conventionally, there is known a radar device that transmits a frequency-modulated continuous-wave signal and calculates a distance to a target and a relative velocity to the target from a difference in frequency between a transmission wave and a reflected wave.
As such a radar device, there has been proposed a radar device that detects a target on the basis of peaks of powers at respective frequencies obtained as a result of frequency analysis of a received signal (hereinafter, referred to as a “frequency spectrum”) (for example, see Japanese Patent Application Laid-open No. 2011-47806).
However, the above-described conventional technology has a problem that it is difficult to detect a target at a short distance from the radar device.
Specifically, peaks on a frequency spectrum may include not only a peak corresponding to a target but also a harmonic wave peak corresponding to a frequency of an integral multiple of a frequency of the peak. In this case, as a distance to the target is shorter, a difference in frequency between peaks is smaller, thus the peaks overlap with each other.
Therefore, when a target exists at a short distance from the radar device, a peak corresponding to the target is hidden by a harmonic wave peak, which makes it difficult to detect the target. Incidentally, this problem is likely to be exposed in a case of tracking control of an object being at a short distance from the radar device as a target like vehicle congestion tracking.